The paper by Booth and Dixon ``A Discontinuity in the Thermoelectric Power of Rhodium'' is critically reviewed. The care necessary in the application of the method of least squares to physical data is discussed with references to articles giving detailed treatments. The method of least squares is then applied to Booth and Dixon's data. It is shown that: 1. The conclusions drawn by Booth and Dixon are invalid because based upon an invalid use of the method of least squares. 2. Their data are inadequate to prove the existence of a discontinuity. 3. No discontinuity of the order of magnitude reported by Booth and Dixon exists in the thermoelectric power of rhodium in the neighborhood of 1100°C. 4. No valid evidence has been adduced for a change in structure of rhodium in the neighborhood of 1100°C. In fact evidence is to the contrary. 5. Other reported ``irregularities'' of the behavior of rhodium in the neighborhood of 1100°C can reasonably be ascribed to the formation and decomposition of a surface film of rhodium oxide.

An apparatus is described for determining the transmission of slow electrons through thin collodion films. The range in accelerating voltages used was from 800 to 34,000 ev and the film thicknesses from 10−3 to 7×10−6 cm.

An improved vacuum type self‐balancing centrifuge which is driven by air is described. It is especially suited for spinning rotors larger than 2 inches in diameter at very constant temperatures. Either the ``quantity'' or ``analytical'' type of rotor may be used with the same driving mechanism.